<!DOCTYPE html>
<title>CSS Anchor Positioning: try-tactic under different writing modes</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#typedef-position-try-fallbacks-try-tactic">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  @position-try --pf {
    left:10px;
    top:20px;
  }
  #cb {
    position: absolute;
    width: 400px;
    height: 400px;
    border: 1px solid black;
  }
  #target {
    position: absolute;
    left: 99999px; /* force fallback */
    width: 30px;
    height: 40px;
    background-color: skyblue;
  }
</style>
<div id=cb>
  <div id=target></div>
</div>
<script>

  function test_try_tactic_wm(try_tactic, writing_mode, direction, expected_offsets) {
    target.style.positionTryFallbacks = `--pf ${try_tactic}`;
    target.style.writingMode = writing_mode;
    target.style.direction = direction;
    test(() => {
      assert_equals(target.offsetLeft, expected_offsets.left, 'offsetLeft');
      assert_equals(target.offsetTop, expected_offsets.top, 'offsetTop');
      assert_equals(target.offsetWidth, expected_offsets.width, 'offsetWidth');
      assert_equals(target.offsetHeight, expected_offsets.height, 'offsetHeight');
    }, `${try_tactic} ${writing_mode} ${direction}`);
  }

  test_try_tactic_wm('', 'horizontal-tb', 'ltr', {left:10, top:20, width:30, height:40});

  // Effectively flips left:10px to right:10px:
  test_try_tactic_wm('flip-inline', 'horizontal-tb', 'ltr', {left:360, top:20, width:30, height:40});

  // Effectively flips top:20px to bottom:20px:
  test_try_tactic_wm('flip-inline', 'vertical-lr', 'ltr', {left:10, top:340, width:30, height:40});

  // Mirror across the [left,top]=>[bottom,right] diagonal:
  test_try_tactic_wm('flip-start', 'horizontal-tb', 'ltr', {left:20, top:10, width:40, height:30});

  // Mirror across the [right,top]=>[bottom,left] diagonal:
  test_try_tactic_wm('flip-start', 'horizontal-tb', 'rtl', {left:340, top:360, width:40, height:30});

</script>
